1. Field of the Invention
Aspects of the present invention relate to an organic lighting emitting diode display device (OLED display device) and a method of fabricating the same, and more particularly, to an OLED display device including a hole injection layer, formed by thermal evaporation using an inorganic semiconductor material, which can be thermally evaporated, and a method of fabricating the same.
2. Description of the Related Art
An OLED display device comprises a substrate, an anode disposed on the substrate, an emission layer disposed on the anode, and a cathode dispose on the emission layer. In such an OLED display device, when a voltage is applied between the anode and the cathode, a hole (positively charged particle) and an electron are injected into the emission layer, and then recombined to create an exciton, which transitions from an excited state to a ground state, to thereby emit light.
The OLED display device may comprise at least one selected from the group consisting of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. The hole injection layer can be disposed between the anode and the emission layer to effectively inject the hole from the anode into the emission layer. In a conventional OLED display device, these layers are organic thin films formed of an organic material. However, especially, the hole injection layer formed of an organic material has some problems, for example, poor interface characteristics with an anode formed of a transparent conductive material, such as, indium tin oxide (ITO) or indium zinc oxide (IZO), and damage occurring when the anode is formed by sputtering. Moreover, the hole injection layer cannot completely protect the underlying emission layer from the damage.